physical education. n. (Education) training and practice in sports, gymnastics, etc, as in schools and colleges. Abbreviation: PE. physâ²ical educaâ²tion. n. instruction in sports, exercise, and hygiene, esp. as part of a school or college program.
3. Stress/injury. Stress on the tissues or any type of injury in the mouth can cause canker sores. Since the sores are actually tiny ulcers, they can be caused by any kind of hard brushing or eating something that can cause bruises or lead to tissue inflammation in the mouth.
There are various causes of blood blisters inside of cheeks and other parts of the mouth as follows: 1  Herpes simplex virus that causes cold sore can cause blood blisters in the mouth. The blisters may erupt after a few days of infection. 2  Some people are allergic to some allergens that are found in food.